Rocking-chair



Oct. 23, 1928. 1,688,587

F. J. LILJEDAHL ROCKING [CHAIR Filed July 8, 1926 IN V EN TOR.

Patented Oct. 23, 192a.-

PATENT OFFICE.

FRANS J. LILJ'EDAHL, OF OAKLAND, CALIFORNIA.

ROCKING-CHAIR.

Application filed July 8,

My invention relates to rocking chairs and is more especially directedto that type of rocking chair having a non-rocking floor pedestal forits support, and to a chair utilizing spring means to stabilize thechair.

It is an object of my invention to provide a rocking chair of thedescribed type in which a spring supplements the tendency of gravity,throughout the rocking range, to urge the loaded chair to its centralposition of equilibrium.

It is a further object of my invention to provide a chair constructionin which a single spring suffices to balance the chair.

It is further the object of my invention to provide a rocking chairhaving an unusually velvety action; that is, in which spring restraintincreases in substantially more than direct proportion to thedisplacement of the chair seat from its central normal position.

Other objects of my invention deal with the lightness and simplicity ofconstruction made possible by my improved design, and together withfurther objects ancillary to and independent of the above listedobjects, will become apparent in the specification.

Referring to the drawings:

Figure 1 is a side elevation of the chair of my invention. The dashlines represent the positions of the chair seat and of the spring axiswhen an occupant of the chair leans back.

Fig. 2 is a front elevation of the chair.

Fig. 3 is a fragmentary section through the pivotal axis of the chair,to disclose the spring and one of the two pivot pins. The plane ofsection is indicated by a line 3-3 in Fig. 1.

Fig. 4c is a detail side elevation of the pivot pin apart from itssocket.

Fig. 5 is a detail of the eye-bolt which is used to attach the spring.

A forked pedestal consisting of uprights 2, 4, joined by a crosspiece 6,and having legs at its base, forms the supporting member for my rockingchair, and is adapted to rest immovably on the floor when in service.

The top portions of the uprights arp apertured to receive the hollowbearing sleeves 8, by which the movable portion of the rocking chair issupported.

The movable portion 10, of the rocking chair, broadly termed the chairseat, includes the arms 12, the back 14:, and the bottom 16, as well asthe connecting braces 18 and 20.

Pivot pins 22 are provided for each side of the chair, and are receivedby the hollow bear- 1926. Serial No. 121,095.

ing sleeves 8. These pins are attached by integral screw plates 24 tothe center braces 20 at each side of the chair seat.

l [t 1s fparticularly pointed out, that the we ght 0 the chairoccupantis swung below the axis about which the rockin part of the chair pivots.This underslung eature minimizes the tendency for the chair to tip toofar, and permits the use of relatively light restraining means.

Resilient means are provided as an aid to gravity in keeping the chairrighted. A coil spring 26 is attached at its upper end to the bottom ofthe chair seat by an eyebolt fitting 28, and at its lower end to thecross-piece 6 of the pedestal by an eyebolt 30. The parts are soapportioned that when the chair is in normal position with the bottom ofits seat substantially horizontal, the spring 26 is substantiallyvertical, is contracted to its fullest extent, and has its axisintersecting the axis of the pivot pins 22. By this arrangement, asingle spring suffices to restrain the chair against excesslve motion inboth directions. This single spring moreover, accomplishes its purposein a most efficient manner, since it offers little retardation for thefirst few degrees of angularity of the rocking of the chair seat fromnormal position, and increases thereafter substantially as the sine ofthis angle. This trigonometric relation is not exact because theangularity of the spring itself must be taken into account, but it willbe noted from Fig. 1, that the stretching imparted to the spring 26 'sgreater for a slight rocking movement wheia the chair is tipped farback, than it is for the same amount of rocking movement when the chairis nearly horizontal. This construction makes for velvety chair actionas well as eflicient spring utilization.

It will be appreciated that various modifications of my device comewithin the purview of my invention. For example, when unitary springmeans are recited, the use of a pair of springs in tandem is-notprecluded. I desire to not be limited beyond the scope of the appendedclaims to my invention.

7 I claim:

1. A swinging chair comprising a seat portion and. arm portions, apedestal pivotally supporting said swinging chair at the arm portionsthereof, and resilient means connected at one end to said pedestal andat its opposite end to said seat portion, said latter connection beingin vertical alignment with at one end to said pedestal and at itsopposite the first named connection and the pivotal end to said seatportion, said latter connec- 10 axis between the pedestal and armportions tion being in vertical alignment with the first when the chairis in normal position. named connection and the pivotal axis be- 2. Aswinging chair comprising a seat portween the pedestal and arm portionswhen the tion and arm portions, a pedestal pivotally chair is in normalposition. supporting said swinging chair at the arm In testimonywhereof, I aflix my signature. portions thereof, and a coil springconnected FRANS J. LILJEDAHL.

